1. Field of the Invention
This invention relates to a device for mechanically and electrically connecting printed wiring boards or sheets.
2. Description of the Prior Art
In recent years, electronic developments leading to size-reduction in various precision instruments and appliances have been under way. For example, in the field of photographic and cinematographic cameras, a number of electronic parts are incorporated therein, and the main bodies of such cameras have been made smaller and lighter. On account of such reduction in size, the space for electrical wiring within the camera has become narrower and narrower. In reflection of such circumstances, there are now used, for the purpose of effectively utilizing the limited space in the camera, many numbers of printed wiring boards such as printed base plates or flexible printed sheets, which are capable of achieving high density wiring in the interior of the cameras.
For joining contacts in these printed wiring boards, there have generally been adopted soldering and pressure welding. The soldering, however, has such a disadvantage that the soldered part lacks flexibility and, moreover, the land is prone to separate from the board or sheet. Therefore, this method is not suitable for connection of the flexible printed wiring boards or sheets which are used in most cases by being bent or curved in a narrow space of the camera, and so forth. In view of such shortcoming in the soldering method, the connection of the contact points has been done mostly by the pressure welding in recent years.
The pressure welding method for joining the contact points, however, is difficult in adjustment of tightening force applied to the printed wiring boards or sheets as put together. If it is too strong, the conductor patterns on the printed wiring boards are damaged or the insulation layers thereon are broken; inversely, if the tightening force is too weak, the contacts are separated from each other to become unable to conduct electrically, both cases bringing about inconveniences in connecting the printed wiring boards.